Effects of different doses of dexmedetomidine combined with stellate ganglion block in patients undergoing laparoscopic radical resection of colorectal cancer

We aimed to expound the effects of different doses of dexmedetomidine (Dex) combined with stellate ganglion block (SGB) on postoperative pain, sleep quality, and serum orexin A levels in patients undergoing general anaesthesia for laparoscopic radical resection for colorectal cancer (CRC).This prospective randomised controlled trial enrolled 320 CRC patients, randomly assigned to four groups (<i>n</i> = 80): control (0.9% NaCl + SGB), and three Dex groups receiving low, medium, or high Dex infusion (0.2, 0.4, and 0.6 µg/kg·h, respectively) combined with SGB. Postoperative pain [Visual Analogue Scale (VAS), postoperative days 1-3], insomnia [Athens Insomnia Scale (AIS), before and after surgery], serum orexin-A levels (enzyme-linked immunosorbent assay), and adverse events were assessed and compared.All Dex groups showed lower VAS scores (postoperative days 1-3), postoperative AIS scores, and serum orexin-A levels than the control group (<i>p</i> < 0.05). These improvements were dose-dependent, with the high-dose group demonstrating the most significant effects. The incidence of adverse events was lower in the Dex groups, with no significant differences across dosage levels (<i>p</i> > 0.05).Dex at 0.6 µg/kg·h combined with SGB provides optimal postoperative analgesia, improves sleep quality, lowers serum orexin-A, and does not significantly increase adverse events.